About the event
The Gene and Linda Voiland School of Chemical Engineering and Bioengineering is hosting a seminar presented by Dr. Abhaya Datye, Distinguished Regents’ Professor & Department Chair, Department of Chemical & Biological Engineering, University of New Mexico.
Abhaya Datye has been on the faculty at the University of New Mexico since 1984. Abhaya received his Ph.D. in chemical engineering from the University of Michigan. He has authored 247 publications, 6 patents and has presented 165 invited lectures around the world including the Europacat at Innsbruck, Austria, Faraday Discussion at Liverpool in the UK, WE Heraeus conference in Bad Honnef, Germany, the School for Electron Microscopy at Berlin and the Taniguchi conference in Japan. His published work has received ~14,643 citations with an h-index of 63 (Google Scholar). He is a fellow of the AIChE, the Microscopy Society of America and the Royal Society of Chemistry. He is involved in international collaborations, having led the successful NSF Partnership for International Research and Education (PIRE) on Conversion of Biomass derived reactants into Fuels, Chemicals and Materials (a collaboration between faculty and researchers in the US, Denmark, Germany, Netherlands and Finland). He has also done sabbaticals at BP in the UK, at Haldor Topsoe in Denmark and extended visits to the Univ. of Poitiers in France and the University of Witwatersrand in South Africa where he was appointed honorary professor. He has been actively involved in the North American Catalysis Society, serving as co-chair for the Denver NAM 2017, program co-chair for the Snowbird NAM 1995. He was the Chair of the Gordon Research Conference on Catalysis in 2010.
His research group has pioneered the development of electron microscopy tools for the study of catalysts. Using model catalysts, his group has shown metal/support interfaces can be studied at near atomic resolution, making electron microscopy – a bulk technique – into a very sensitive and local probe of surface structure, which determines catalytic activity. His current work involves the synthesis of biorenewable chemicals, fundamental studies of catalyst sintering, and synthesis of novel nanostructured heterogeneous catalysts, especially the stabilization of isolated single atoms on supports. His research has been recognized through numerous awards, including John Matthews Lectureship, Microscopy Society of South Africa, 2013, NSF Industry University Cooperative Research Centers, 2008 Award for Excellence, Best paper Materials Science, Microscopy and Microanalysis, 2006, and Outstanding Research Award and Outstanding Teaching Award from the School of Engineering at the University of New Mexico. In 2016, the ACS publication Chemical & Engineering News included his research on single atom catalysis as one of the top 10 stories for the year.
Tuning Interactions between Single Atoms and Catalyst Supports: Key to the Design of Thermally Stable and Regenerable Catalysts
Single atom catalysts represent a new frontier in heterogeneous catalysis because of improved atom efficiency, higher reactivity and improved selectivity for a range of catalytic reactions. However, isolated atoms become mobile at elevated temperatures, causing agglomeration into nanoparticles. Our research team has been actively studying the mechanisms of catalyst sintering and approaches for regeneration of platinum group metals on oxide catalyst supports.
The initial catalyst, as-synthesized, contains exclusively Pt single atoms . Fig 1a shows the light-off during CO oxidation. In the as-prepared, single atom state (light blue), the catalyst shows very poor reactivity for CO oxidation. Activating the catalyst by CO reduction at 275°C (dark blue) yields a catalyst very active for low temperature CO oxidation. If this catalyst is calcined at 600 °C in air (red), simulating high temperature lean oxidation conditions, the catalyst activity declines, but the activity can be restored by CO reduction at 275 °C (orange). This catalyst supported on ceria is thus fully regenerable and changes from a high reactivity (metallic Pt, Fig. 1b) into single atom (ionic Pt, Fig. 1c) state. The facile regeneration is made possible by the ability of ceria to bind Pt strongly under oxidizing conditions and to release the Pt atoms readily during reducing conditions. The removal of Pt creates active ceria which facilitates low temperature CO oxidation. The presentation will describe the mechanistic underpinnings of this unusual behavior.
Ceria supports help generate a stable and fully regenerable Pt catalyst that can change reversibly from single atom form into metallic nanoparticles . Trapping of platinum group metals on oxide supports is central to making catalysts regenerable. We will show how the understanding derived from ceria supports can be translated to other oxide supports, helping to create stable and regenerable catalysts. This will impact not only automotive exhaust treatment (where catalysts are exposed to this high temperature) but also for other industrial reactions where heterogeneous catalysts are used.